1. Field of the Invention
The invention relates to a method for building a foundation for a structure comprising a plurality of segments, in particular for a wind turbine tower. The invention also relates to a support pole, a foundation segment for such a structure and a wind turbine.
2. Description of the Related Art
Constructing a permanently stable and level foundation is of enormous importance for larger structures. Particularly in the case of a wind turbine tower, which can be more than 100 m in height and be exposed in operation to enormous forces, the foundation must conform to exacting specifications.
Wind turbine foundations are currently constructed by firstly making a so-called subbase in a foundation bed, in other words a cement or concrete base layer that is as level and horizontal as possible. Support poles for setting down the foundation segment on the subbase are then mounted on the foundation segment, i.e., the lowermost segment of a tower comprised of several segments. In order to compensate for any unevenness in the subbase and to align the foundation segment as horizontally as possible, the support poles can be screwed varying depths into the underside of the foundation segment, the support poles being configured for this purpose as threaded poles in at least the upper section facing the underside of the foundation segment.
There have been cases in which support poles have either penetrated into the subbase or broken off from the underside of the foundation segment as a result of the enormous lateral loads exerted on the support poles by the foundation segment, which can currently weigh between 10 and 14 metric tonnes. This has resulted in the foundation segment overturning. In addition to the dangers to which persons engaged in constructing the foundation were exposed, this has led not only to delays but also to additional costs for remedying the damage caused.